Additive manufacturing also improves geometric tolerances.

An increasing number of industrial plants are reducing the spare parts inventories stored at their facilities. At the same time, they are replacing fewer pumps because of capital constraints and have determined that remanufacturing existing equipment is the best path forward. Many of the pumps within these facilities have exceeded 50 years of service. This drives the need for replacement parts and, in some cases, emergency replacement parts. Considering the age of these pumps, the replacement parts from the manufacturer are likely obsolete and may not be easily available. Further complicating the situation is the location of manufacture. Many cast parts are manufactured outside the U.S and have long lead times.

To address these challenges, many companies are developing technologies to meet the specific and growing demands of the industry. Many of these advanced tools, including coordinate measure machine (CMM) technology, allow for quicker emergency repairs, faster deliveries and higher quality pump parts.

Emergency equipment repairs are common throughout the industry. Having fewer spare parts makes this classification of repair more challenging. Standard equipment repairs typically take six to eight weeks, while emergency repairs must be completed within one day to three weeks, depending on the severity of the situation.

This type of repair often drives the need for rapidly supplied cast parts, which traditionally require long lead times because of the use of wooden tooling to create the mold to manufacture the casting.

Recent advancements in 3-D technology, known as additive manufacturing, allow the cast parts manufacturer to meet customer demands by eliminating the need to create traditional tooling.

Vertical Condensate Extraction Pump Upgrade

Station History
Eraring Power Station, located in the coal belt area at Lake Macquarie on the central coast of New South Wales, began generating in 1982, with all four units commissioned between 1982 and 1984. Formerly state owned under the banner of Eraring Energy until mid 2013, the station is now owned by Origin Energy, one of Australia’s largest electricity generators and retailers.

The power station underwent a significant upgrade during 2010 to 2012, increasing the output of all four generating units from 660MW to 720MW each. Eraring is the largest generating unit in the Origin group and has established itself as Australia’s largest power station since the upgrade.

Condensate Extraction Pumps
The pumps are the standard arrangement of condensate extraction pump used in the power generation industry: underfloor, vertically mounted, canned design, 4 stages with a double suction impeller and inline suction and discharge ports. Each of the four generating units has two 100% duty pumps, driven by a 1850kW 4 pole, electric motor.

Problems
For more than a few years, the life of the thrust bearing has been subjected to scrutiny after causing numerous premature failures and constant concern for the Station Operators, Maintenance Engineers and Management. The thrust bearing design was typical for the period that the pumps were manufactured, tapered back to back roller design incorporating both thrust and radial loads and the drive coupling configuration as part of the bearing cartridge.

Station Engineers had been researching the upgrade design options for a period of time, calling on the original equipment manufacturer, aftermarket service centres and bearing manufacturers for input and options to overcome this troublesome plant and work towards the best possible solution.

Contract Overview
In 2012, Eraring Energy released a tender for the upgrade project to several service providers. The project included a sizeable work scope including design and supply of a new white metal bearing cartridge with an appropriate pedestal and several other new components.

The contract specifications require maintaining the same pump drive couplings, electric motor, mechanical seal cartridge and as many of the original pump components, meaning there was substantial engineering work required by the Hydro Australia Engineers.

Contract Award
A contract of this size was sought after by several original equipment manufacturers and Hydro Australia Pty. Ltd. located in the Gippsland region at Morwell Victoria was awarded the contract late in 2012. The contract runs for a period of 4 years with the first pump installation completed in April 2013 and the final pump due for installation in 2016.

Additional Requirements & Spare Pump
With the knowledge and experience of Hydro Australia with the supply of engineered spare parts, a major undertaking was to supply and a complete new discharge head, a first for Hydro Australia. The 2.5 m high and 1.7 m wide discharge head is the most significant component of the pump as it ties everything together. Other new components were manufactured by Hydro Australia including impellers, stage cases, wear rings, couplings and shafts. The new components complete with the stations spare parts, enabled a complete spare pump to be manufactured. This spare pump gives flexibility and relieves time critical exchanges and on the run maintenance. Continue reading →

Hydro is a global leader in the pump aftermarket repairs, upgrades and engineering solutions.

Pump companies typically fall into one of two categories: the original equipment manufacturer (OEM) that design, build, and sell pumps; and smaller, local machine repair shops. But Hydro offers the pump industry the best of both worlds. George Harris, one of the original founding engineers and current CEO, explains Hydro’s unique worldwide market position: “We have developed a unique niche where we have the engineering services, the testing capabilities, and the

worldwide footprint that the large OEMs have, but we still maintain the exibility and the cost-effectiveness of the smaller companies.”

Harris also emphasizes that engineers are the heart of the company. Nick Dagres, the Vice President of Nuclear Operations in Chicago, notes that “We focus on aftermarket services and support. We implement engineering modifications to improve the performance of pumps that are out in the field.” By offering pump rebuilding, engineering, and upgrading at each service centre, Hydro can more effectively service the special needs and requirements of customers in each region. Staying close to the customer is one of the fundamental tenets of Hydro’s strategy and culture.

(Left) Hydro’s long list of services include welding-related repairs, such as performed on this 2 ½” Pacific RL IJ charging pump. (Right) A thorough quality inspection is carried out by Hydro’s detail oriented engineers.

Industrial equipment users are often confronted with pump parts issues and must make choices. Handling these issues requires making experience-based decisions and prioritizing. How pump hydraulic and wear components in existing inventory are treated is an issue that merits consideration. Plant size, age, past purchasing, maintenance and storage-related practices are among the factors that affect a facility’s status with respect to operational readiness and downtime risk.

As these generally-known facts are applied on a pump component level, it is often determined that the specific pump components in the storehouse may not be the same as the components currently operating in a particular process centrifugal pump. Nor is it always the case that truly optimized components are presently installed. Therefore, the risk of experiencing unforeseen downtime can be reduced by having the right parts on hand. If the parts are truly optimized, installing them at the next opportunity will take the facility beyond being back in business—it will actually take the equipment owners to greater profitability.

To ensure that pumps will perform their intended functions, inventoried or stocked parts should be thoroughly inspected and corrected as needed prior to installation. Incoming inspection is practiced by best-of-class equipment owners and only verified-as-correct parts will be placed in the storehouse. This case study examines a real-life scenario and demonstrates essential precautions that can be taken when procuring pump hydraulic and wear components.

A Condensate Pump Repaired & Improved

During a planned outage, a nuclear power plant (NPP) sent a three-stage condensate pump to a highly experienced service center with hydraulic pump design engineers on staff. The NPP provided the hydraulic components, wear rings and bearings from its stock inventory for the pump rebuild project. The hydraulic pump design engineers at the service center performed a thorough inspection of both the disassembled rotor and the parts supplied by the NPP. A visual inspection quickly revealed that the geometry of the replacement impellers did not match the impellers that were removed from the disassembled pump (see Figure 1).

Figure 1. Cross-section of a three-stage pump created by an experienced pump repair facility for this three-stage pump. Note semi-open impellers in stages two and three.

A Hydro East welder repairs the impeller of a Foster Wheeler circulating water pump.

A Hydro East welder repairs the impeller of a Foster Wheeler circulating water pump.

During the 2012 refueling and maintenance outage at Unit 1 of the two-unit Calvert Cliffs nuclear power plant, near Lusby, Md., Hydro East, a subsidiary of Hydro Inc. based in Aston, Pa., supported the on-site overhaul of two large circulating water pumps. Used to supply cooling water to the plant, the Foster Wheeler vertical pumps are 8 ft 3 in. in diameter, 11 ft 5 in. tall, and weigh approximately 25,000 lb.

After the 2012 refueling outage was completed, Calvert Cliffs engineers and Hydro East’s field service team convened to discuss the project, review lessons learned, and generate plans for making the 2013 refueling outage at Unit 2 even more efficient and cost-effective. In preparation, the two groups reviewed the process that had been used in 2012 to remove, rebuild, and reinstall the Unit 1 circulating water pumps, which had been rebuilt on-site. Hydro East’s field service technicians reconditioned the impellers on location, and the Fort Smallwood Fabrication Shop gathered the other parts required to complete the rotating assemblies. The complete disassembly of an entire pump took four 12-hour
shifts, requiring one shift to clean all the reusable parts and another shift to flip and stage the parts. Each shift required a significant number of site resources as well—including security, a crane, and the crane operator—and because other tasks being performed during the outage required the use of some of these same resources, the field service technicians experienced substantial downtime.

To eliminate downtime caused by plant-induced delays—such as having to wait for the crane to become available or for spare parts to be machined—Calvert Cliffs decided to remove the Unit 2 circulating water pump rotating assemblies in one piece and send them to the Hydro East service center to be rebuilt. This plan enabled Calvert Cliffs to achieve cost savings by maximizing the availability of its internal resources and by reducing the number of shifts needed to remove
the pump assemblies from four 12-hour shifts to two. More important, lifting the assemblies in one piece eliminated two high-risk rigging activities for each pump.

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Hydro Worldwide

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About Us

Our mission is to work hand-in-hand with our valued customers to optimize the performance and reliability of their pumping systems by evaluating and understanding root causes of pump degradation or failure and by providing unbiased engineering analysis, quality workmanship, and responsive field service for improved plant operation.